I recently got on the PTR and started messing around with a premade Hunter. I really focused on the new families that are available on the PTR: Water Striders and Basilisks. First off: on the PTR the quest strider Boglash in Zangarmarsh is no longer the albino model (probably to make the rare one in MoP more "special") but now uses the green model. I also went into the Underbog and the Black Stalker is indeed tameable. I personally prefer the green skin, but it's nice to know the black one is there too and much easier to get than running SSC.
As for Basilisks, I tried the green ones and the purple ones in Terokkar Forest and they were both tameable. However, I personally don't like how they run, so I won't be getting one on live when they're available. Still, neat pets. I really wish they would have given us Hydras finally, but oh well. I did actually try to tame a Hydra too.
As a final note, it's interesting to see my bow on my back instead of a spear/staff/whatever. I kind of like it, to be honest.